> Which hwloc branch is destined for ompi-1.5.5?
> Once I known I can test the appropriate hwloc RC on all my platforms.

1.3.latest, so svn.open-mpi.org/svn/hwloc/branches/v1.3.

It's not that far from what is already in hwloc 1.5, but there were a few additional bug fixes, so it seems like a good idea to do an actual final hwloc 1.3.x release and put that in OMPI 1.5.x/1.6.x so that it can have a long shelf life.